ec/google/chromeec: Fix acpi_name() for Chrome EC device
In ACPI tables, Chrome EC device (CREC - HID GOOG0004) is a child of
EC device (EC0 - HID PNP0C09). However, in coreboot device tree, there
is no separate chip/device for EC0. Thus, acpi_name() needs to return
EC0.CREC as the ACPI name for the Chrome EC device. By returning the
ACPI name as EC0.CREC, all devices that live under Chrome EC device
can simply call acpi_device_path()/acpi_device_scope() to emit the
right path/scope.
In the future, if we ever add a special chip driver for handling EC0
(HID PNP0C09), then the ACPI name for Chrome EC can be fixed to return
CREC.
BUG=b:154290952
TEST=Verified that acpi_device_path()/acpi_device_scope() return the
correct name for Chrome EC device.
Signed-off-by: Furquan Shaikh <furquan@google.com>
Change-Id: Iec4b0226d1e98ddeb0f8ed8b89477fc4f453d221
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40513
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/ec/google/chromeec/ec_acpi.c b/src/ec/google/chromeec/ec_acpi.c
index a7e3ae5..79e3f4b 100644
--- a/src/ec/google/chromeec/ec_acpi.c
+++ b/src/ec/google/chromeec/ec_acpi.c
@@ -17,13 +17,21 @@
#include "ec.h"
#include "ec_commands.h"
-#define GOOGLE_CHROMEEC_USBC_DEVICE_PARENT "CREC"
#define GOOGLE_CHROMEEC_USBC_DEVICE_HID "GOOG0014"
#define GOOGLE_CHROMEEC_USBC_DEVICE_NAME "USBC"
const char *google_chromeec_acpi_name(const struct device *dev)
{
- return "EC0";
+ /*
+ * Chrome EC device (CREC - GOOG0004) is really a child of EC device (EC - PNP0C09) in
+ * ACPI tables. However, in coreboot device tree, there is no separate chip/device for
+ * EC0. Thus, Chrome EC device needs to return "EC0.CREC" as the ACPI name so that the
+ * callers can get the correct acpi device path/scope for this device.
+ *
+ * If we ever enable a separate driver for generating AML for EC0 device, then this
+ * function needs to be updated to return "CREC".
+ */
+ return "EC0.CREC";
}
static const char *power_role_to_str(enum ec_pd_power_role_caps power_role)
@@ -190,8 +198,7 @@
if (google_chromeec_get_num_pd_ports(&num_ports))
return;
- /* Add TypeC device under the existing device + ".CREC" scope */
- acpigen_write_scope(acpi_device_path_join(dev, GOOGLE_CHROMEEC_USBC_DEVICE_PARENT));
+ acpigen_write_scope(acpi_device_path(dev));
acpigen_write_device(GOOGLE_CHROMEEC_USBC_DEVICE_NAME);
acpigen_write_name_string("_HID", GOOGLE_CHROMEEC_USBC_DEVICE_HID);
acpigen_write_name_string("_DDN", "ChromeOS EC Embedded Controller "